London has been battered by 50mph winds that have felled trees and caused travel chaos. Powerful gusts swept across the capital as the Met Office issued a yellow "be aware" weather alert for most of the country.

A flagship Government scheme aimed at making homes more energy efficient has gone live amid claims that hundreds more households than thought have signed up for assessments.

Ministers said the Green Deal would bring about a revolution in energy efficiency - and provide a much needed boost to the economy.

And officials at the Department for Energy and Climate Change (DECC) said anecdotal information from suppliers suggested hundreds of household have been assessed for the Green Deal - but said precise numbers could not be revealed because they were being collated for official statistics.

Reports had earlier suggested just five assessments had been carried out ahead of Monday's launch, which will see Government-backed loans available for energy efficiency work made available for the first time.

Deputy Prime Minister Nick Clegg said: "The Green Deal will help thousands of homes stay warm for less. Those people will benefit from energy saving improvements - and their energy bills will fall. The UK green sector is a success story - it is the sixth largest in the world and has a crucial part to play in building a strong economy. The Green Deal will support thousands of jobs - not just over the next few years, but in the long-term."

Energy and Climate Change Secretary Edward Davey added cutting energy use was the best defence against rising bills. He said: "The Green Deal is a great deal. Improve the look and feel of your home, make it cosier and at the same time save energy - what's not to like?"

The Green Deal involves having a home reviewed by an accredited assessor, who will look at what upgrades can be made and over what time period energy savings would cover the cost of the work.

Green Deal Providers then quote for the work and households can get multiple quotes for some or all of the work. If they proceed, a Green Deal Installer will carry out the work. The cost is covered by a loan via the Green Deal Finance Company and repayments are added to the cost of the household electricity bill. The company has been created as a not-for-profit institution tasked with the costs of the loan as low as possible.

A DECC spokesman said tweets from two Green Deal assessors suggested hundreds of assessments were taking place. He said Green Place had commented on January 23 that "we have already completed over 100 assessments with 1800 in the wings" while Ampere GDP said on January 19: "Ampere GDP has already conducted over 40 Green Deal Advice Reports this week alone."

But Ed Matthews, head of fuel poverty campaign group Energy Bill Revolution, said the Government's flagship plan did not go far enough. He said: "The Green Deal and Energy Company Obligation, will not stop fuel poverty rocketing in the face of high gas prices."